JP2017150364A - Control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge air in a lash adjuster with a simple configuration.SOLUTION: A control device for controlling a variable displacement oil pump for supplying oil to a lash adjuster which swingably supports a rocker arm includes an acceleration sensor for measuring acceleration of a vehicle, and a pump control section for controlling driving of the variable displacement oil on the basis of the acceleration measured by the acceleration sensor. Accordingly, air can be discharged from the lash adjuster with a simple configuration.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a control device that controls a variable displacement oil pump that supplies oil to a lash adjuster that supports a rocker arm in a swingable manner.

  Conventionally, an engine is provided with a lash adjuster for swingably supporting a rocker arm. The lash adjuster has a main body portion and a plunger, and the valve clearance of the rocker arm can be adjusted by changing the protruding amount of the plunger from the main body portion by the hydraulic pressure of oil supplied by an oil pump.

  In the lash adjuster, when air is mixed into the oil supplied from the oil pump, problems such as failure to appropriately change the protruding amount of the plunger and generation of abnormal noise occur.

  Therefore, a control mechanism has been proposed in which the bubble rate in the lash adjuster is measured by a Coriolis meter, and the auxiliary oil pump is driven when the bubble rate exceeds a preset danger value.

JP 2005-282510 A

  In the above control mechanism, it is necessary to provide an auxiliary pump for discharging the air in the lash adjuster in addition to the oil pump that supplies oil to each part of the engine. It was.

  Accordingly, an object of the present invention is to provide a control device that can discharge air in a lash adjuster with a simple configuration.

  In order to solve the above problems, a control device of the present invention is a control device that controls a variable displacement oil pump that supplies oil to a lash adjuster that swingably supports a rocker arm, and measures vehicle acceleration. An acceleration sensor; and a pump control unit that drives and controls the variable displacement oil pump based on the acceleration measured by the acceleration sensor.

  An integrated acceleration is derived by integrating the acceleration measured by the acceleration sensor over a predetermined measurement period, and the integrated acceleration is equal to or greater than a predetermined threshold at which air flows into the lash adjuster together with oil. An air inflow determination unit that determines whether or not the variable displacement oil pump is in the pump control when the integrated acceleration is determined to be greater than or equal to the threshold by the air inflow determination unit. It is good to drive so that it may become more than predetermined oil pressure.

  The variable displacement oil pump further includes an execution condition determination unit that determines whether or not an execution condition for performing a drive for discharging the air that has flowed into the lash adjuster is satisfied. When the integrated acceleration is determined to be greater than or equal to the threshold by the air inflow determination unit and the execution condition determination unit determines that the execution condition is satisfied, the variable displacement oil pump is set to the hydraulic pressure or higher. It is good to drive so that it becomes.

  A temperature sensor that measures the temperature of the oil; and a rotational speed sensor that measures the rotational speed of the engine. The execution condition is that the temperature measured by the temperature sensor is equal to or higher than a predetermined first temperature. And it is good that it is less than 2nd temperature higher than this 1st temperature, Comprising: The said rotation speed measured by the said rotation speed sensor is less than predetermined rotation speed.

  Moreover, the said acceleration sensor is good to measure the acceleration of the horizontal direction of the said vehicle.

  According to the present invention, the air in the lash adjuster can be discharged with a simple configuration.

It is the schematic which shows the structure of an engine system. It is a figure explaining the structure of a valve operating mechanism. It is a figure explaining the structure of a lash adjuster. It is a flowchart which shows the flow of control processing.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a schematic diagram showing the configuration of the engine system 1. As shown in FIG. 1, the engine system 1 includes an engine 2 and a control device 3.

  The engine 2 includes a cylinder block 10, a crankcase 12 integrally formed with the cylinder block 10, a cylinder head 14 joined to the cylinder block 10, and an oil pan 16 joined to the crankcase 12. . In FIG. 1, the cylinder block 10, the crankcase 12, the cylinder head 14, and the oil pan 16 are shown in a cross-sectional view.

  A plurality of cylinder bores 18 are formed in the cylinder block 10, and pistons 20 are slidably supported on the connecting rods 22 in the plurality of cylinder bores 18, respectively. In the engine 2, a space surrounded by the cylinder bore 18, the cylinder head 14, and the crown surface of the piston 20 is formed as a combustion chamber 24.

  In the engine 2, the internal space of the crankcase 12 and the internal space of the oil pan 16 communicate with each other to form a crank chamber 26. The crankshaft 28 is rotatably supported in the crank chamber 26 by the crankcase 12 and supports the connecting rod 22 rotatably.

  The cylinder head 14 is provided with an intake port 30 and an exhaust port 32 so as to communicate with the combustion chamber 24. The leading end of the intake valve 34 is located between the intake port 30 and the combustion chamber 24, and the leading end of the exhaust valve 36 is located between the exhaust port 32 and the combustion chamber 24.

  Further, in the engine 2, the intake valve 34 and the exhaust valve 36 are moved so as to come into contact with and separate from the valve seats of the intake port 30 and the exhaust port 32 by a valve operating mechanism 50 (see FIG. 2) described below. . Thereby, the intake valve 34 opens and closes between the intake port 30 and the combustion chamber 24, and the exhaust valve 36 opens and closes between the exhaust port 32 and the combustion chamber 24.

  FIG. 2 is a schematic cross-sectional view of the valve mechanism 50. In the engine 2 of the present embodiment, two intake valves 34 and two exhaust valves 36 are provided for each cylinder bore 18. Further, the valve operating mechanism 50 is also provided for each of the intake valve 34 and the exhaust valve 36. However, since the basic configuration of the valve operating mechanism 50 is the same, here, one exhaust valve 36, One valve mechanism 50 that opens and closes the valve is described with reference to the drawings, and the description of the valve mechanism 50 of the intake valve 34 is omitted.

  As shown in FIG. 2, the valve operating mechanism 50 supports a cam 52 that interlocks with the rotation of the crankshaft 28 (see FIG. 1), a rocker arm 54 that swings as the cam 52 rotates, and the rocker arm 54. And a lash adjuster 56 (HLA (Hydraulic Lash Adjuster)).

  The cam 52 is fixed to the cam shaft 58 and rotates integrally with the cam shaft 58. The engine 2 includes a timing belt (not shown) that transmits the rotational power of the crankshaft 28 to the camshaft 58. The timing belt is wound around the crankshaft 28 and the camshaft 58, and the camshaft 58 rotates integrally with the crankshaft 28.

  The cam 52 has an outer peripheral surface composed of a non-lift surface 52a and a lift surface 52b continuous with the non-lift surface 52a. The non-lift surface 52a is a surface having the same distance from the rotation center and located within the same radius, and the lift surface 52b is a surface in which the distance from the rotation center gradually increases toward the vertex 52c farthest from the rotation center. It is.

  The rocker arm 54 includes a roller surface 54a that contacts the non-lift surface 52a and the lift surface 52b of the cam 52. The roller surface 54a is formed by a circular arc surface having a constant curvature, and the width thereof is substantially equal to the widths (thicknesses in the rotation axis direction) of the non-lift surface 52a and the lift surface 52b of the cam 52.

  Further, the rocker arm 54 is formed with a pivot receiver 54b on one end side (left side in the figure) of the roller surface 54a. The pivot receiver 54b is a semispherical recess formed on the surface opposite to the surface facing the cam 52, and the tip of the lash adjuster 56 contacts. On the other hand, a pressing portion 54c is formed on the other end side (right side in the drawing) of the rocker arm 54 with respect to the roller surface 54a. The pressing portion 54c is configured by a curved surface provided on the same surface side of the rocker arm 54 as the pivot receiver 54b.

  The exhaust valve 36 includes a valve stem 36c having a valve head 36a formed at the distal end and a valve stem end 36b at the proximal end, and is slidably held on the cylinder head 14. Specifically, a through hole 14b is formed in the cylinder head 14, and a valve stem 36c is slidably inserted into a valve stem guide 60 fitted in the through hole 14b.

  In the valve stem 36c, an upper spring seat 62a and a lower spring seat 62b are provided on the valve stem end 36b side of the through hole 14b. Between the upper spring seat 62a and the lower spring seat 62b, a valve is provided. A spring 64 is provided. The valve spring 64 is composed of a compression coil spring, and the upper spring seat 62a and the lower spring seat 62b act on elastic forces that are separated from each other in the axial direction of the valve stem 36c. Due to the elastic force of the valve spring 64, the exhaust valve 36 is always urged toward the valve stem end 36b, and the valve head 36a is seated on the valve seat 32a to close the intake port 30.

  The lash adjuster 56 is provided in a receiving hole 14c formed in the cylinder head 14, and supports the rocker arm 54 so as to be swingable.

  FIG. 3 is a schematic diagram showing the configuration of the lash adjuster 56. As shown in FIG. 3, the lash adjuster 56 includes a main body 70, a plunger 72, a plunger spring 74, a check ball 76, a check ball cage 78, and a check ball spring 80. In the following description, the upward direction in the figure is simply referred to as the upward direction, and the downward direction in the figure is simply referred to as the downward direction.

  The main body 70 is formed in a bottomed cylindrical shape. The plunger 72 has a substantially cylindrical shape and a tip end portion formed in a hemispherical shape. The plunger 72 is accommodated in the main body portion 70 so as to be movable in the axial direction. The plunger spring 74 is interposed between the bottom portion inside the main body 70 and the plunger 72. The check ball 76 is biased by the check ball spring 80 in the check ball cage 78 and is also biased by the plunger spring 74 via the check ball cage 78 to open and close an opening 72 a formed at the center of the bottom of the plunger 72. I do.

  An oil hole 70 a is formed on the side surface of the main body 70. The plunger 72 is formed with an oil hole 72b on the side surface. An oil passage 72 c that connects the oil holes 70 a and 72 b is formed between the inner wall of the main body 70 and the outer wall of the plunger 72. The oil hole 70a is connected so as to communicate with an oil passage 14d (see FIG. 12) described later.

  In the lash adjuster 56, a space between the bottom of the main body 70 and the plunger 72 and in which the plunger spring 74 is disposed is formed as the high pressure chamber 82, and a space in the plunger 72 is formed as the low pressure chamber 84.

  When the rocker arm 54 swings and a pressing force is applied to the tip of the plunger 72 from the pivot receiver 54b, the high-pressure chamber 82 closes the opening 72a of the plunger 72 with the check ball 76 so that the tip of the plunger 72 is locked to the rocker. Even when a pressing force is received from the arm 54, the pressure becomes difficult to be compressed.

  When the rocker arm 54 swings upward due to the upward movement of the exhaust valve 36, the plunger spring 74 follows the pivot receiver 54b of the rocker arm 54 by the biasing force of the plunger spring 74, and the plunger 72 moves upward. Move in the direction. At this time, the pressure in the high-pressure chamber 82 decreases, and the check ball 76 opens the opening 72a so that oil flows.

  In addition, a top hole 72d is provided vertically through the upper end of the plunger 72 in the radial direction, and the outer peripheral surface of the plunger 72 and the pivot receiver 54b pass through the low pressure chamber 84 and the top hole 72d. Oil is supplied and lubricated.

  In this way, the lash adjuster 56 can adjust the valve clearance of the rocker arm 54 by changing the protruding amount of the plunger 72 from the main body 70.

  Returning to FIG. 1, the cylinder head 14 is provided with a spark plug 38 so that the tip is located in the combustion chamber 24. Then, the air-fuel mixture flowing into the combustion chamber 24 via the intake port 30 is ignited and burned by the spark plug 38 at a predetermined timing. Due to such combustion, the piston 20 reciprocates, and the reciprocating motion is converted into rotational motion of the crankshaft 28 through the connecting rod 22.

  A variable capacity oil pump 40 is connected to one end of the crankshaft 28. The variable displacement oil pump 40 is operated by the rotational movement of the crankshaft 28, pumps up oil stored in the oil pan 16 through the strainer 42, and pumps (supplies) the oil to each part of the engine 2. The lash adjuster 56 is supplied with oil via the oil passage 14d.

  As will be described in detail later, the variable displacement oil pump 40 can adjust the amount of oil to be discharged, that is, the hydraulic pressure, based on the control of the control device 3 (pump control unit 94).

  The control device 3 includes an ECU (Engine Control Unit) 4, an acceleration sensor 5, a rotation speed sensor 6, and a temperature sensor 7. The acceleration sensor 5 measures the acceleration in the horizontal direction (front-rear direction and left-right direction) of the vehicle. The rotation speed sensor 6 measures the rotation speed of the engine 2 (crankshaft 28). The temperature sensor 7 measures the temperature of the oil (oil temperature).

  In the engine system 1 configured as described above, when horizontal acceleration occurs in the vehicle, the oil stored in the oil pan 16 is moved in the oil pan 16 due to the acceleration, and the variable displacement oil pump 40 is aired together with the oil. It will happen that it will be pumped up.

  Then, when oil containing air is supplied to the lash adjuster 56, a malfunction such as the plunger 72 not moving as designed with respect to the main body portion 70 or an abnormal noise occurs. .

  Therefore, the ECU 4 determines whether air is flowing into the lash adjuster 56 based on the acceleration measured by the acceleration sensor 5. When the ECU 4 determines that air is flowing into the lash adjuster 56, the ECU 4 increases the amount of oil (hydraulic pressure) discharged by the variable displacement oil pump 40 and discharges air from the lash adjuster 56.

  Specifically, the ECU 4 is a microcomputer including a central processing unit (CPU), a ROM storing programs, a RAM as a work area, a storage unit such as a flash memory, and the like. It functions as a condition determination unit 92 and a pump control unit 94.

  FIG. 4 is a flowchart showing the flow of the vehicle control process. As shown in FIG. 4, when the engine 2 is started, the air inflow determination unit 90 resets the accumulated acceleration (S100), acquires the vehicle acceleration measured by the acceleration sensor 5 at predetermined intervals, An integrated acceleration obtained by accumulating the acceleration every time it is acquired is derived (S102).

  When the air inflow determination unit 90 integrates the acceleration over a predetermined measurement period (for example, 60 seconds) to derive the integrated acceleration, the air is flowing into the integrated acceleration and the lash adjuster 56. The threshold value to be compared is compared (S104). In other words, here, it is determined whether or not the variable displacement oil pump 40 pumps air together with the oil and the air flows into the lash adjuster 56 due to the occurrence of the horizontal acceleration in the vehicle. Become.

  As a result, if the integrated acceleration is less than the threshold value (NO in S104), the air inflow determination unit 90 returns to the process of S100, resets the integrated acceleration, and starts deriving the integrated acceleration again.

  On the other hand, when it is determined by the air inflow determining unit 90 that air is flowing into the lash adjuster 56 (YES in S104), the execution condition determining unit 92 uses the air that has flowed into the lash adjuster 56 by the variable displacement oil pump 40. It is determined whether or not an execution condition for performing an operation for forcibly discharging is satisfied (S106).

  As an execution condition, the oil temperature measured by the temperature sensor 7 is equal to or higher than a predetermined first temperature (for example, 60 ° C.) and lower than a second temperature (for example, 120 ° C.) higher than the first temperature. In addition, the rotational speed of the engine 2 measured by the rotational speed sensor 6 is set to be less than a predetermined rotational speed (for example, 2000 rpm). When the oil temperature is lower than the first temperature (60 ° C.), the oil has a high kinematic viscosity, so that the oil does not easily flow to the lash adjuster 56. When the oil temperature is equal to or higher than the second temperature (120 ° C.) Since the kinematic viscosity is low and oil cannot be supplied to the lash adjuster 56 with the target hydraulic pressure, it is excluded from the execution conditions. Further, when the rotational speed of the engine 2 is equal to or higher than the predetermined rotational speed (2000 rpm), the hydraulic pressure of the oil discharged by the variable capacity oil pump 40 is sufficient to discharge the air from the lash adjuster 56. As a result, it is excluded from the execution conditions.

  When it is determined by the execution condition determination unit 92 that the execution condition is satisfied (YES in S106), the pump control unit 94 causes the variable displacement oil pump 40 to run for a predetermined duration (for example, 10 minutes). Then, air discharge control is performed to drive the oil pressure to be 300 kPa or more (S108). Thereby, air can be discharged from the lash adjuster 56.

  Further, when the execution condition determining unit 92 determines that the execution condition is not satisfied (NO in S106), and the pump control unit 94 causes the variable displacement oil pump 40 to have a hydraulic pressure of 300 kPa or more over a continuous period. After driving in this manner (S110), the air inflow determination unit 90 returns to the process of S100, resets the integrated acceleration, and then starts to derive the integrated acceleration again.

  As described above, the control device 3 drives and controls the variable displacement oil pump 40 based on the acceleration measured by the acceleration sensor 5. Specifically, the control device 3 integrates the accelerations measured by the acceleration sensor 5 to derive the integrated acceleration, so that the variable displacement oil pump 40 pumps air together with oil from the oil pan 16 by the horizontal acceleration. Then, it is determined whether or not air has flowed into (mixed into) the lash adjuster 56.

  When the integrated acceleration is equal to or greater than the threshold value, the control device 3 determines that air is flowing into the lash adjuster 56, and the variable displacement oil pump 40 is kept at least when the engine 2 is idling for a continuous period. Or, it is driven so that the hydraulic pressure is higher than in the case of driving with a low load (in this embodiment, 300 kPa or more).

  Thus, the control device 3 can discharge air from the lash adjuster 56 with a simple configuration even when idling or when driving with a low load.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and various modifications within the scope described in the claims. Needless to say, the modified examples also belong to the technical scope of the present invention.

  In the above embodiment, when the execution condition is established by the execution condition determination unit 92, the pump control unit 94 drives the variable displacement oil pump 40 so that the hydraulic pressure becomes 300 kPa or more over the continuous period. However, the execution condition determination unit 92 may not determine whether or not the execution condition is satisfied. That is, when the air inflow determination unit 90 determines that air is flowing into the lash adjuster 56, the pump control unit 94 always causes the variable displacement oil pump 40 to have a hydraulic pressure of 300 kPa or more over the continuous period. You may make it drive.

  INDUSTRIAL APPLICABILITY The present invention can be used for a control device that controls a variable displacement oil pump that supplies oil to a lash adjuster that swingably supports a rocker arm.

2 Engine 3 Control device 4 ECU
5 Acceleration Sensor 6 Rotational Speed Sensor 7 Temperature Sensor 16 Oil Pan 40 Variable Capacity Oil Pump 56 Rush Adjuster 90 Air Inflow Determination Unit 92 Execution Condition Determination Unit 94 Pump Control Unit

Claims (5)

A control device that controls a variable capacity oil pump that supplies oil to a lash adjuster that supports a rocker arm in a swingable manner,
An acceleration sensor for measuring the acceleration of the vehicle;
A pump controller that drives and controls the variable displacement oil pump based on the acceleration measured by the acceleration sensor;
A control device comprising: An integrated acceleration is derived by integrating the acceleration measured by the acceleration sensor over a predetermined measurement period, and the integrated acceleration is equal to or greater than a predetermined threshold at which air flows into the lash adjuster together with oil. An air inflow determination unit for determining whether or not
The pump controller
The variable displacement oil pump is driven so as to be equal to or higher than a predetermined hydraulic pressure when the integrated acceleration is determined to be equal to or higher than the threshold by the air inflow determination unit. Control device. An execution condition determination unit for determining whether or not an execution condition for performing driving for discharging the air flowing into the lash adjuster by the variable capacity oil pump is satisfied;
The pump controller
When the integrated acceleration is determined to be greater than or equal to the threshold by the air inflow determination unit, and the execution condition determination unit determines that the execution condition is satisfied, the variable displacement oil pump is moved to the hydraulic pressure. The control device according to claim 2, wherein the control device is driven to achieve the above. A temperature sensor for measuring the temperature of the oil;
A rotation speed sensor for measuring the rotation speed of the engine,
The execution condition is as follows:
The temperature measured by the temperature sensor is equal to or higher than a predetermined first temperature and lower than a second temperature higher than the first temperature, and the rotation speed measured by the rotation speed sensor is a predetermined rotation. The control device according to claim 3, wherein the control device is less than a number. The acceleration sensor is
The control device according to any one of claims 1 to 4, wherein acceleration in a horizontal direction of the vehicle is measured.

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